Constraining accuracy of the pairwise velocities in N-body simulations using scale-free models
- Sorbonne Université, Paris (France); Max Planck Inst. fuer Extraterrestrische Physik, Garching (Germany)
- Harvard-Smithsonian Center for Astrophysics, Cambridge, MA (United States)
- Flatiron Institute, New York, NY (United States)
- Sorbonne Université, Paris (France)
We present a continuation of an analysis that aims to quantify resolution of N-body simulations by exploiting large (up to N = 40963) simulations of scale-free cosmologies run using abacus. Here, we focus on radial pairwise velocities of the matter field, both by direct estimation and through the cumulative two-point correlation function (using the pair conservation equation). We find that convergence at the 1 per cent level of the mean relative pairwise velocity can be demonstrated over a range of scales, evolving from a few times the grid spacing at early times to slightly below this scale at late times. We show the analysis of two different box sizes as well as from averaging results from the smaller boxes, and compare the power of the two aforementioned estimators in constraining accuracy at each scale. Down to scales of the order of the smoothing parameter, convergence is obtained at ∼5 per cent precision, and shows a behaviour indicating asymptotic stable clustering. In conclusion, we also infer for LCDM simulations conservative estimates on the evolution of the lower cut-off to resolution (at 1 and 5 per cent precision) as a function of redshift.
- Research Organization:
- Harvard Univ., Cambridge, MA (United States); UT-Battelle LLC/ORNL, Oak Ridge, TN (United States)
- Sponsoring Organization:
- National Aeronautics and Space Administration (NASA); USDOE; USDOE Office of Science (SC)
- Grant/Contract Number:
- AC05-00OR22725; SC0007881
- OSTI ID:
- 2280394
- Journal Information:
- Monthly Notices of the Royal Astronomical Society, Journal Name: Monthly Notices of the Royal Astronomical Society Journal Issue: 1 Vol. 525; ISSN 1365-2966; ISSN 0035-8711
- Publisher:
- Oxford University PressCopyright Statement
- Country of Publication:
- United States
- Language:
- English
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